THIS invention relates to a tube squeezing device for squeezing deformable tube containers such as toothpaste tubes.
One problem encountered with toothpaste tubes and the like is that they are squeezed randomly in such a fashion that not all of the contents are dispensed, and the remaining contents are wasted when disposed of in the mangled tube.
U.S. Pat. No. 4,337,879 discloses one type of squeezing device which aims to overcome this problem. One drawback associated with the squeezing device of this patent is that it does not provide for differences in thickness between metal and plastic tubes. Further, it generally does not rid the tube of those contents which are in the region of the neck of the tube.
According to the invention there is provided a device for squeezing a deformable tube having a closed end and a nozzle end and containing a material to be dispensed, the device including:
a housing;
mounting means for mounting the tube relative to the housing;
a slide arranged to be moved along a linear path defined in the housing;
a first roller mounted rotatably on the slide about an axis perpendicular to the direction of movement of the slide;
a second opposed roller mounted rotatably on the slide about an axis substantially parallel to the axis of the first roller;
activating means for allowing the rollers to rotate simultaneously towards one another from a roller advancing position to a tube squeezing position,
wherein each of the first and second rollers have first and second respective cammed faces defining in combination a slide advancing nip in the roller advancing position for allowing the rollers to advance relative to a squeezed portion of the tube and a tube squeezing nip in the tube squeezing position, the tube squeezing nip being narrower than the slide advancing nip, for squeezing the material from an adjacent unsqueezed portion of the tube.
Typically, a tube gripping nip is defined between the advancing nip and the tube squeezing nip.
Conveniently, the slide advancing nip is defined by a pair of opposed and substantially parallel slide advancing faces formed on the first and second rollers.
Preferably, the tube squeezing nip is defined by a pair of opposed and substantially parallel tube squeezing faces formed on the first and second rollers, the tube squeezing faces extending substantially transversely relative to the slide advancing faces.
Advantageously, the tube gripping nip is defined by a pair of tube gripping faces extending between the slide advancing faces and the tube squeezing faces, with the tube gripping faces including tube gripping formations for gripping the tube firmly as the tube squeezing faces are rotated towards one another.
Typically, the tube gripping formations are toothed or serrated formations and are arranged to crimp the tube therebetween, with the teeth of the tube gripping faces at least partly enmeshing.
Conveniently, the tube squeezing faces are relatively smooth for allowing the slide to be advanced when the tube squeezing faces are opposed, so as to evacuate the tube contents in the region of the neck of the tube.
Preferably, the device includes biasing means for biasing the rollers to an inoperative position in which the slide advancing faces of each roller lie adjacent the squeezed portion of the tube.
Advantageously, the activating means includes an activating lever for rotating the first roller and co-acting means for allowing the first roller to rotate the second roller so that both rollers rotate simultaneously towards one another.
The co-acting means preferably includes intermeshing teeth on the rollers, the teeth being arranged to co-operate to allow both rollers to rotate simultaneously.
Conveniently, the housing is pivotably mounted to a backing plate, the backing plate including a tube retaining base for receiving the neck of the tube.
Typically, the tube retaining base includes a pair of inwardly projecting arms, the arms being arranged to resiliently splay downwardly and outwardly when the neck of the tube is inserted therein so as to clamp the neck of the tube firmly in position.